August 6, - August 8, 2019

Thanks to Block Scientific, I was able to procure the re-certified Bayer DCA 2000+ without hassles and get the lab back in operation. The
device works perfectly and I look forward to doing more business with Block Scientific.

Tuberculosis IgA // IgM // IgG (EIA-4250 // EIA-4251 // EIA-4252)

Intended Use

DRG Tuberculosis ELISA has been designed for the detection of IgG / IgM / IgA antibodies against Mycobacterium tuberculosis in serum and plasma. Further applications in other body fluids are possible and can be provided on request.

Principle of the Test

The principle of the test reaction can be described in four stages.

Serum incubation
Specific antibodies bind to the antigens on the solid phase to form a stable immune complex.
After a 60 minutes incubation at room temperature the wells are washed with prediluted wash buffer to remove all nonreactive serum components.

Conjugate incubation
The anti-human-IgG /-IgM /-IgA horseradish peroxidase conjugate is added to all wells. The conjugate binds to IgG / IgM / IgA antibodies on the solid phase antigen to form a stable sandwich. After a 30 minutes incubation at room temperature the excess conjugate is removed by washing all wells with washing buffer.

Substrate reaction and stopping
The TMB substrate is dispensed into each well and the peroxidase enzyme/substrate reaction forms a stable blue chromogen. The reaction and subsequently the colour development is stopped after 20 minutes incubation at room temperature by adding 0.5 M H2SO4 to the wells. The change in pH also causes the chromogen to change colour from blue to yellow.

Reading and interpretation
The intensity of the colour is read in a microtiter plate reader at 450 nm (recommended reference wavelength for bichromatic measurement: 600–690 nm). The intensity of the colour (OD) is directly proportional to the concentration of the specific antibody in the donor sample.